Various types of exercising apparatuses intended to develop and condition muscles are known in the art. Many of such apparatuses have been developed to establish optimal resistance to a force applied by the user of the apparatus throughout the entire exercise routine. Moreover, such apparatuses have attempted to eliminate the need for using a variety of different exercise equipment in performing exercises for building the strength and endurance of specific muscles and muscle groups.
Optimal physical results are known to be achieved when a relatively constant resistive force to exercise movement is maintained throughout an exercise routine. Isotonic-type exercise devices frequently rely upon free weights to provide resistance to an exerciser's movements. At some point during an exercise routine, however, the force applied due to the weights will vary as a result of the characteristic motion of a free weight during weight lifting exercises. Thus, a constant resistive force cannot be maintained.
Isokinetic exercise apparatuses, which typically employ hydraulic control systems, provide resistance proportional to the force exerted. Typically, variation of the resistance imposed on the exerciser through a particular exercise movement is permitted. For example, U.S. Pat. No. 4,863,161 Telle, Sep. 5, 1989, discloses an isokinetic apparatus which combines a weight lifting bar with a hydraulic control circuit to control the degree of resistance imposed throughout each range of movement of an exercise. The system, however, does not establish a uniform resistance at the onset or completion of a particular exercise movement. Additionally, pump powered pneumatic or hydraulic-system exercise machines do not permit the force profile to vary with individual user variations in force and range of movement.
Exercise apparatuses using elastic cords or springs to provide a desired resistive force have been developed. U.S. Pat. No. 5,074,551, Olschansky et al., Dec. 24, 1991, discloses a multiple exercise system wherein resistive force is supplied by a pair of flexible members maintained at a minimum predetermined tension by a tensioning system. The resistive force is linearly displaced using a rotatively actuated bar. The amount of tension on the system, however, can not be adjusted quickly or during an exercise routine without the exerciser having to stop exercising to make the adjustment. Moreover, each tension setting is for a set amount of resistance, therefore, the amount of tension applied cannot be adjusted in varying or very small amounts.
U.S. Pat. No. 4,961,573, Wehrell, Oct. 9, 1990, discloses a harness having elastic cords for providing resistance to boxing motions. The harness fits over the upper torso of a boxer and a system of pulleys in the harness position the elastic cords near the armpits of the boxer. Hand grips attached to the cords are used by the boxer to practice the sport specific movements of boxing, particularly, arm, hand, and reflex-type motions. The apparatus, however, will not be of much use to a person exercising for overall strengthening and conditioning.
U.S. Pat. No. 4,328,964, Walls, May 11, 1982, discloses a multiple sport exerciser having a handle attached to a plurality of elastic ropes. The handle may simulate the handle of a tennis racket, a baseball bat, golf club, or other sporting equipment. The device is anchored to a door frame, and the user positions himself as he would if playing the particular sport associated with the selected handle. The user practices his "swing" by swinging the handle forward in the manner used in the sport.
U.S. Pat. No. 4,685,670, Zinkin, Aug. 11, 1987, discloses an exercising apparatus, which may be secured to a doorway. Flexible cables threaded through multiple pulleys provide resistance to a user's movement. The pulleys allow adjusting the length of the flexible cables, thereby increasing or decreasing the resistance applied by the cables against exercise motions. Pretension is set, and must be adjusted when less or greater tension and resistance to exercise is desired. These apparatuses only provide resistance to a user's arm movements and do not allow a user to exercise other muscle groups which are frequently of equal or greater importance in successfully playing a sport.
U.S. Pat. No. 4,863,163, Wehrell, Sep. 5, 1989, and U.S. Pat. No. 4,968,028, Wehrell, Nov. 6, 1990, disclose vertical jump exercise apparatuses wherein a sophisticated tracking means directs elastic cords fastened to the waist of a user to provide a nearly constant resistive force to jumping on a base. The speed of leg motor reflexes will be increased by vertical jump conditioning, however, associated motor reflexes, such as hip rotation, can not be improved using the disclosed apparatuses. Hip rotation speed and strength have been found to be essential to achieving top athletic performance. Moreover, an exerciser can not train for a particular sport and perform a weight training program using the same apparatus. Thus, there remains a need for a multiple sport training and exercise apparatus which provides a means for a user to condition and improve the motor reflexes of all major muscles specific to a particular sport and to perform a complete weight training routine.
There is also a need for an exercise apparatus which allows a user to perform only eccentric or concentric movements over a wide range of angles. The ability to perform only eccentric or concentric movements is particularly important to successfully rehabilitating damaged or injured muscles.